Make 2-inch-long deep cut with knife parallel to cutting board in center of each chicken breast half to form pocket. Evenly stuff pockets with cheese and tomatoes; secure with wooden toothpicks. Sprinkle, if desired, with salt and pepper. Dip chicken breasts in flour.
Heat oil in 12-inch skillet over medium-high heat and brown chicken. Add garlic and cook, stirring occasionally, 30 seconds. Stir in Sauce and simmer covered 6 minutes or until chicken is thoroughly cooked. Remove toothpicks. Serve, if desired, over hot steamed escarole or spinach.